import java.util.PriorityQueue;

/**
 * @author: gao
 * @create-date: 2025/3/6 11:15
 */

class Student{

}

public class Test {
    public static void main(String[] args) {
        PriorityQueue<Integer> queue = new PriorityQueue<>();
        queue.offer(null);
    }

    public static void main2(String[] args) {
        PriorityQueue<Student> queue = new PriorityQueue<>();
        queue.offer(new Student());
    }

    public static void main1(String[] args) {
        PriorityQueue<Integer> queue = new PriorityQueue<>();
        queue.offer(10);
        queue.offer(4);
        queue.offer(7);

        System.out.println(queue.poll());
        System.out.println(queue.peek());
        System.out.println(queue.poll());
        System.out.println(queue.poll());
        System.out.println(queue.poll());
    }
}